Investigation of Acidic Fibroblast Growth Factor Delivered Through a Collagen Scaffold for the Treatment of Full-Thickness Skin Defects in a Rabbit Model

Abstract

In this study the wound healing response of full-thickness skin defects was enhanced through the use of acidic fibroblast growth factor using a collagen scaffold. The objectives of this study were (1) to compare the facilitatory effects of acidic fibroblast growth factor on the cellular response (fibroblast, neutrophil, macrophage, epithelial), tissue response (angiogenesis, collagen) and mechanical properties in a healing wound; and (2) to determine the effect of a collagen scaffold on wound healing when compared with the control. Three 3 x 3 cm full-thickness defects were created on the dorsi of 15 New Zealand White rabbits. Each rabbit had a control (no treatment), collagen scaffold, and collagen scaffold with FGF-1 (100 microg/cm2). All the wounds were covered with a transparent polyurethane dressing. There were three periods of study (1, 2, and 3 weeks) with five rabbits in each period. The volume fraction of the tissue and cells was histomorphometrically determined for each wound. The acidic fibroblast growth factor/collagen system showed promise in enhancing the healing process. Acidic fibroblast growth factor/collagen treatment increased angiogenesis, enhanced epithelialization, and reduced contraction rate over the control. A higher inflammatory response was indicated in the collagen scaffold treated group. Hence acidic fibroblast growth factor delivered through a collagen scaffold shows promise in future clinical applications.

To Cross-Link or Not to Cross-Link? Cross-Linking Associated Foreign Body Response of Collagen-Based Devices

“…The most common small animal model for collagen-based devices in vivo characterisation is the subcutaneous implantation in mouse or rat for up to a month in duration 21,143 . A rat full-thickness skin defect model has also been used to evaluate the wound healing ability of collagen materials combined with plastic dressings in acute and chronic wounds 144,145 . The rabbit ear model has also been used to study specific wounds, such as burns 146 Table 2).…”

An Overview of Methods for theIn VivoEvaluation of Tissue-Engineered Skin Constructs

“…202 Pandit et al tested the mechanical strength (ultimate tensile strength, stiffness, and failure strength) of explanted regenerating skin in time after treatment of rabbit wounds with a collagen scaffold with and without FGF-1 or TGF-b, and untreated wounds. 179,183,185 They used an Instron tester to evaluate 1Â4 cm skin strips in uniaxial tension and calculated the ultimate tensile strength, modulus of elasticity, and strain-to-failure. Valuable information can thus be obtained, but the relatively large samples that are required may be a limiting factor.…”

“…145 Pandit et al used the Image Based Analysis System (IBAS) (formerly sold by Kontron, Eching/Mü nchen, Germany) to quantify contraction, epithelialization, volume fractions of different cell types, and blood vessels on H&E-stained sections. 179,183,185,187,188 This is also possible by using pixel intensities to quantify tissue and fibroblast ingrowth, 200 which can be performed using freely available software like ImageJ (http://rsbweb.nih.gov/ij/).…”

Nanotechnology for Nanomedicine and Delivery of Drugs

“…In such products, cells are seeded within the fibrous scaffolds or matrix, which may degrade or dissolve as the new tissue is formed. In any of these situations, precise control over cellular environment is essential, with the delivery as appropriate of molecular signals provided by growth factors, angiogenic factors and also mechanical signals [93,94].…”